I just had a Steam update for this game, so I'm assuming that the trainer will need to be updated as well.

---------------------------------------------------------------------------Kill a thousand men and they will hate you. Kill a million men and they will queue to face you. But kill a single man and they will see monsters and devils in every shadow.

Edit: I downloaded the latest trainer and seems now with that recent patch for MW3 the game closes/crashes as soon as you enable the trainer. Did they install a security that crashes the game. I ran it as administrator and I also noticed that it said on the bottom right side that a (Anti-Cheating) was enabled.